* Obama critical of Poland's constitutional court overhaul
* Polish government downplays his comments
* Last-minute changes fail to make an impact (Adds Poland comment, details)
By Ayesha Rascoe
WARSAW, July 8 (Reuters) - U.S. President Barack Obama expressed concern on Friday over Poland's moves to shackle its constitutional court, in unusually blunt comments calling on the former communist EU country's government to do more to protect democracy.
Speaking alongside President Andrzej Duda after they met at a NATO summit in Warsaw, Obama said the ruling conservatives had taken some steps to address U.S. and European concerns but more should be done. Duda did not respond, and Polish officials later sought to play down the comments.
"I expressed to President Duda our concerns over certain actions, and the impasse over Poland's constitutional tribunal," Obama told reporters.
"I insisted that we are very respectful of Poland's sovereignty and I recognise that parliament is working on legislation to take some important steps, but more work needs to be done," the U.S. leader said.
Obama's criticism follows an unprecedented decision by the European Commission earlier this year to open an investigation into whether government policies threaten the rule of law. The EU probe, which can ultimately lead to the suspension of a member state's voting rights, is still open.
Critics say the government's changes to the constitutional tribunal undermine democratic standards and are part of a broader push to seize more control over state institutions, charges the ruling Law and Justice (PiS) party denies.
Duda's spokesman Marek Magierowski belittled Obama's criticism.
"President Obama made his statement, president Duda made his," Magierowski told reporters. "It's difficult to force president Obama to say what this or that politician in Poland would like him to say. I don't see a problem here."
BACKBONE OF DEMOCRACY
The eurosceptic PiS rushed through parliament an amended version of the reforms on Thursday, in an apparent effort to reassure its western allies over the issue. But opposition critics said the change fell short of what was needed to preserve democratic checks and balances.
The government, which has also come under criticism over rules allowing for more state surveillance and public media reforms, argues it is only trying to make the constitutional court more effective and transparent.
Speaking to reporters with Duda at his side, Obama said an independent judiciary was the backbone of democracy.
"As your friend and ally we urged all parties to work together to sustain Poland's democratic institutions," he said.
"That's what makes us democracies, not just ... the fact that we vote in elections, but the institutions we depend on every day such as rule of law, independent judiciaries."
A Polish government spokesman, asked about Obama's criticism, said legislative changes to the court rules were still being finalised.
"The parliamentary majority is trying to finalise the conflict, presenting compromise proposal," Rafal Bochenek said.
PiS won a landslide election last October, unseating long-ruling centrists on a promise of more economic fairness and national pride. Its popularity remains strong, driven by increased welfare spending, but its efforts to exert control on state institutions have deeply polarised the Polish society. (Additional reporting by Pawel Sobczak, Wiktor Szary and Marcin Goettig in Warsaw; Writing by Justyna Pawlak; Editing by Paul Taylor)
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